1. Field of the Invention
The present invention relates to a binding for footwear, such as a boot, on a gliding board, such as a ski or a snowboard, and to a gliding board equipped with such a binding.
2. Background Information
A binding for securing a boot on a gliding board, such as a ski, generally includes a front retaining device, referred to as the “toe-piece”, and a rear retaining device, referred to as the “heel-piece”. The ski boot is interposed between the toe-piece and the heel-piece, these elements being fixed on the ski, i.e., on the gliding board. Thus, the combined action of the two retaining devices makes it possible to affix the boot to the ski longitudinally. To block the vertical movement of the boot, the toe-piece and the heel-piece are equipped with stop mechanisms acting on the boot.
Various solutions exist for making a toe-piece or a heel-piece. For example, the documents EP-A-241 360 (or family member U.S. Pat. No. 4,765,641), EP-A-1 151 765 (or family member U.S. Pat. No. 6,585,283), and EP-A-2 174 695 disclose various toe-piece embodiments. As shown in the drawing figures of these examples, the front retaining device has a pair of front wings forming a “V”, whose legs partially cover a front extension of the ski boot. Moreover, the lower surface of the sole of the boot presses on a support element fixed on the ski. Consequently, the vertical immobilization of the boot in the area of the toe-piece is achieved by this double contact, i.e., the contact between the upper surface of the front extension of the boot and the wings of the toe-piece, on the one hand, and the contact between the sole of the boot and the support element, on the other hand.
For safety reasons, the toe-piece and the heel-piece often incorporate a safety mechanism for releasing the binding if necessary. These mechanisms make it possible to free the user's foot to avoid injuries in the event of an accidental transverse movement of the foot, which may occur during a fall, for example, or, generally speaking, to protect the foot from injuries when the forces exerted on the boot exceed predetermined values. Safety mechanisms for the toe-piece are also described in the documents mentioned above.
There are several types of ski boots, including alpine ski boots and touring ski boots. These two categories are classified by the NF ISO 5355 and NF ISO 9523 standards, respectively. These ski boots distinguish over one another in particular by the dimensions of the portions interfacing with the components of the binding. Due to these substantial dimensional variations, bindings are specific to a category of boot.
Certain toe-pieces include a mechanism enabling elastic adjustment of the height, or vertical positioning, of the wings. This elastic mechanism serves to compensate for small dimensional variations related to the manufacture of boots of the same category.
Similarly, there are bindings whose support element interfacing with the sole of the boot is mounted on an elastic mechanism in order to compensate for the dimensional variations inherent in a boot category.
Other toe-pieces are divided into two portions, the portion incorporating the wings being adjustable in height, via an adjusting screw, with respect to the other portion fixed to the ski. A toe-piece of this type is complex and expensive. This toe-piece is hardly compatible with a mechanism for compensating for the dimensional variations inherent in a category. This design does not make it possible to cover large dimensional variations. In addition, this solution can be fragile in that the portion incorporating the wings is retained only by the adjusting screw. Furthermore, the height adjustment of the wings for compatibility with a boot category is not obvious because the adjustment is endless, with the screw being driven without reference marking. It is therefore not easy to properly adjust the height of the wings for a particular boot category. Moreover, this type of adjustment to adapt to a boot category is not convenient for the user, as it is necessary to move the portion incorporating the wings over a long path, thereby requiring several turns of the screwdriver. Finally, the height configured can be altered relatively easily by acting on the adjusting screw.